[U-Boot] Regression due to 020bbcb "usb: hub: Power-cycle on root-hub ports"

[Stephen Warren]

On 07/08/2013 07:25 AM, Vivek Gautam wrote:
> On Mon, Jul 8, 2013 at 6:33 PM, Marek Vasut <marex at denx.de> wrote:
>>> On Mon, Jul 1, 2013 at 10:11 PM, Stephen Warren <swarren at wwwdotorg.org> wrote:
>>>> On 07/01/2013 07:49 AM, Vivek Gautam wrote:
>>>>> On Sun, Jun 30, 2013 at 10:08 PM, Marek Vasut <marex at denx.de> wrote:
>>>>>>> (Sorry to those on to/cc; I'm resending this so it goes to the correct
>>>>>>> mailing list)
>>>>>
>>>>> Dear Stephen,
>>>>> sorry for the delay in responding to this.
>>>>>
>>>>>>> Commit 020bbcb "usb: hub: Power-cycle on root-hub ports" causes a
>>>>>>> regression on Tegra systems.
>>>>>>>
>>>>>>> The first time "usb start" is executed, it appears to work correctly.
>>>>>>> However, any subsequent time it is executed, it takes a long time, and
>>>>>>> eventually fails to find any USB devices.
...
>>>>>> BUMP? Vivek, any ideas? Otherwise I'm reverting this.
...
>>>>> There's one BUG that i could see in " 0bf796f " commit.
>>>>> Now that we parallelized the sequence to power cycle ports, so if
>>>>> get_port_status for any port failed,
>>>>> it returns from hub_power_on() and not power-on any of the port.
>>>>>
>>>>> Below is the change i suggest.
...
>>>>> can you please confirm if you problem is related to this BUG in the
>>>>> sequence of power-cycling the ports.
>>>>
>>>> I applied that change, and it does not solve the problem on Tegra, nor
>>>> do I see any of the messages that were changed from debug to printf.
...
>>> seaboard which i can see has 3 controllers.
>>
>> Vivek, what do I have to revert to fix this flub? I will do that now, since this
>> discussion is stalled.
> 
> 0bf796f usb: hub: Parallelize power-cycling of root-hub ports
> 020bbcb usb: hub: Power-cycle on root-hub ports
> 
> Above two patches are the one which changed the hub_power_on() functionality.
> If Stephen can confirm that reverting these patches really solves the
> problem on Tegra,
> we can revert them.

Yes, I have been reverting those two commits locally for a while, and it
solves the problem for me.